[0/3] add support for writable bare tracepoint

Message

Hou Tao Sept. 16, 2021, 1:55 p.m. UTC

Hi,

The patchset series supports writable context for bare tracepoint.

The main idea comes from patchset "writable contexts for bpf 
raw tracepoints" [1], but it only supports normal tracepoint
with associated trace event under tracefs. Bare tracepoint
is more light-weight and doesn't have the ABI burden of
normal tracepoint, so add support for it in BPF.

Any comments are welcome.

[1]: https://lore.kernel.org/lkml/[e-mail]

Hou Tao (3):
  bpf: support writable context for bare tracepoint
  libbpf: support detecting and attaching of writable tracepoint program
  bpf/selftests: add test for writable bare tracepoint

 include/trace/bpf_probe.h                     | 19 +++++++--
 tools/lib/bpf/libbpf.c                        |  4 ++
 .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 +++++++
 .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 +++++
 .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
 .../selftests/bpf/prog_tests/module_attach.c  | 40 ++++++++++++++++++-
 .../selftests/bpf/progs/test_module_attach.c  | 14 +++++++
 7 files changed, 101 insertions(+), 6 deletions(-)

Comments

Yonghong Song Sept. 16, 2021, 10:58 p.m. UTC | #1

On 9/16/21 6:55 AM, Hou Tao wrote:
> Hi,
> 
> The patchset series supports writable context for bare tracepoint.
> 
> The main idea comes from patchset "writable contexts for bpf
> raw tracepoints" [1], but it only supports normal tracepoint
> with associated trace event under tracefs. Bare tracepoint
> is more light-weight and doesn't have the ABI burden of
> normal tracepoint, so add support for it in BPF.

Just curious that do you have an actual use case for this?
If that is the case, it would be good that you stated in
the cover letter and relevant commit message.

Also, please add bpf-next to the tag like [PATCH bpf-next x/x]
to make it clear that the patch set is for bpf-next.

> 
> Any comments are welcome.
> 
> [1]: https://lore.kernel.org/lkml/[e-mail]
> 
> Hou Tao (3):
>    bpf: support writable context for bare tracepoint
>    libbpf: support detecting and attaching of writable tracepoint program
>    bpf/selftests: add test for writable bare tracepoint
> 
>   include/trace/bpf_probe.h                     | 19 +++++++--
>   tools/lib/bpf/libbpf.c                        |  4 ++
>   .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 +++++++
>   .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 +++++
>   .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
>   .../selftests/bpf/prog_tests/module_attach.c  | 40 ++++++++++++++++++-
>   .../selftests/bpf/progs/test_module_attach.c  | 14 +++++++
>   7 files changed, 101 insertions(+), 6 deletions(-)
>